Dropped ceiling with eco-friendly ceiling panels

ABSTRACT

This invention relates to a suspended ceiling, comprising a metal grid structure and a plurality of drop-in ceiling panels supported by the metal grid structure. Each of the ceiling panels includes a thermal conductive metal substrate, a heat insulating coating formed on the top surface of the metal substrate, and a thermal conductive ceramic coating formed on the bottom surface of the metal substrate. The heat insulating coating is provided to prevent heat generated in a plenum space between the dropped ceiling and a actual ceiling from traveling down to the room below the dropped ceiling. And, the thermal conductive ceramic coating is provided to enhance a heat transfer capability of the metal substrate. As such, the ceiling panels can facilitate rapid cooling of an air-conditioned room.

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation of co-pending application Ser. No. 15/097,720, filed on Apr. 13, 2016.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a dropped ceiling, and more particularly to a dropped ceiling that includes eco-friendly ceiling panels to promote cooling of an air-conditioned room.

2. Description of the Related Art

Dropped or suspended ceilings are widely used in residential, commercial and industrial buildings. Ceiling panels which define this dropped ceiling are generally suspended by a grid-like support structure. This support structure is secured to the building frame and/or the existing ceiling of the room. The plenum space between the dropped ceiling and the actual ceiling is used for enclosing electrical and communication cables, fire protection, conduits, and ventilation ducts.

Ceiling panels or ceiling tiles used in the dropped ceiling may be designed to serve a variety of functions. First, the panels may be designed to serve as an attractive means for concealing the ducts, wiring, plumbing, etc. located above the panels. Second, the panels have been designed to help create a quiet working atmosphere by absorbing undesired sound or noise produced in the room below. Next, the panels are often designed to contain a material which allows the panels to serve as a fire barrier. Should a fire start in an enclosed room, the panels help contain the fire to that room by preventing the fire from entering the plenum space above the dropped ceiling. Finally, but perhaps most importantly, the panels have been designed to prevent heat generated in the plenum space above the dropped ceiling from traveling down to the room below.

A common construction of the panel combines several layers of materials for the purpose of achieving all desired ceiling panel characteristic. For example, the panel may include a rigid core that is preferably formed of gypsum with low heat conductivity. An upper surface of the gypsum core is covered with a sheet of a reflective metallic material, such as aluminum foil. A lower surface of the gypsum core is covered with a plastic film, formed of a flexible vinyl material, such as polyvinyl chloride (pvc) film. The plastic film has an exposed surface that is provided with a design or other known decorative embellishment. Nevertheless, such a ceiling panel can barely passively prevent the heat generated in the plenum space above the dropped ceiling from entering the room below. The cooling of the room actually depends mostly on the operation of an air conditioner installed in the room, rather than the ceiling panels.

It is known that if you increase the temperature of the thermostat on your air conditioner by one degree, the amount of cooling required by the air conditioner is reduced, and each degree you raise the thermostat can save a great deal of money on electric bills. Thus, there is a desire to produce a dropped ceiling with panels that can actually actively assist the air conditioner to reduce the room temperature.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a dropped ceiling with a novel, unique ceiling panel to actively assist the air conditioner to reduce the room temperature and therefore reduce energy consumption on a daily basis.

Briefly described, the ceiling panel of this invention includes a thermal conductive metal substrate, a heat insulating coating and a thermal conductive ceramic coating. The thermal conductive metal substrate, such as an aluminum alloy sheet, has a top surface facing up toward an actual ceiling of a building, and a bottom surface facing down toward a floor of a room of the building. The heat insulating coating is formed on the top surface of the metal substrate in order to prevent the heat generated in the plenum space between the dropped ceiling and the actual ceiling from traveling down to the room below the dropped ceiling. The thermal conductive ceramic coating is formed on the bottom surface of the metal substrate to enhance a heat transfer capability of the metal substrate.

The heat insulating coating may comprise an organic resin doped with inorganic heat-resistant powder. Preferably, the organic resin of the heat insulating coating is acrylic resin; and the inorganic heat-resistant powder of the heat insulating coating comprises nanoporous silica.

The thermal conductive ceramic coating may comprise an inorganic resin doped with inorganic heat conductive powder. Preferably, the inorganic resin of the thermal conductive ceramic coating is made by a sol-gel process; and the inorganic heat conductive powder of the thermal conductive ceramic coating has at least one material selected from the group consisting of graphite, graphene, Titanium dioxide, Silicone carbide, and mica.

The foregoing and other objectives, features, and advantages of the invention will be more readily understood upon consideration of the following detailed description of the invention, taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a dropped ceiling being employed in an air-conditioned room in accordance with one embodiment of the present invention; and

FIG. 2 is a partially enlarged side view of a ceiling panel used in the dropped ceiling of FIG. 1.

DETAILED DESCRIPTION OF EMBODIMENTS

Referring to FIG. 1, there is shown a preferred embodiment of the dropped ceiling 100 for use in an air-conditioned room. The dropped ceiling 100 generally includes a metal grid structure 1 and a plurality of ceiling panels 2 each dropped in one of the rectilinear openings 10 defined by the metal grid structure 1. In particular, the ceiling panels 2 are configured in a manner that each of them can assist the air conditioner 4 to reduce the temperature of the room in conjunction with a fan 3, as will be discussed in detail later.

As shown in FIG. 2, each of the ceiling panels 2 includes a thermal conductive metal substrate 21, a heat insulating coating 22 formed on a top surface of the metal substrate 21, and a thermal conductive ceramic coating 23 formed on a bottom surface of the metal substrate 21. Specifically, the top surface of the thermal conductive metal substrate 21 faces up toward an actual ceiling of a building, and the bottom surface of the same faces down toward a floor of a room of the building. The metal substrate 21 may be made of Aluminum or aluminum alloy. Aluminum alloy is ideally suited for the metal substrate 21 because it is light in weight, excellent in heat conductivity and low in cost.

The heat insulating coating 22 is formed on the top surface of the metal substrate 21, by spray or flow coating methods, in order to prevent the heat generated in a plenum space between the dropped ceiling 100 and the actual ceiling from traveling down to the room below the dropped ceiling 100. Specifically, the heat insulating coating 22 is substantially made of an organic resin doped with inorganic heat-resistant powder. In this embodiment, the organic resin of the heat insulating coating 22 is made of aqueous acrylic resin. Unlike silicon resin, polyurethane resin or Epoxy resin, the acrylic resin is aqueous and relatively more environmentally friendly. The inorganic heat-resistant powder of the heat insulating coating 22 preferably comprises nanoporous silica that has extremely low thermal conductivity and can provide an efficient thermal isolation. As a result, the heat insulating coating 22 can not only prevent the heat in the plenum space from traveling down to the room in summer, but also keep the heat in the room from dissipating to the plenum space in winter.

The thermal conductive ceramic coating 23 is formed on the bottom surface of the metal substrate 21, by spray or flow coating methods. The thermal conductive ceramic coating 23 is provided to assist heat absorption and/or heat dissipation of the metal substrate 21, and thereby enhance the heat transfer capability of the metal substrate 21. For this purpose, the thermal conductive ceramic coating 23 is substantially made of an inorganic resin doped with inorganic heat conductive powder. In this embodiment, the inorganic resin of the thermal conductive ceramic coating 23 is made by a sol-gel process. The sol-gel process is a wet-chemical technique used for the fabrication of both glassy and ceramic materials. In this process, the sol (or solution) evolves gradually towards the formation of a gel-like network containing both a liquid phase and a solid phase. Typical precursors are metal alkoxides and metal chlorides, which undergo hydrolysis and polycondensation reactions to form a colloid. If the liquid in a wet gel is removed under a supercritical condition, a highly porous material with high surface area is obtained. The basic structure or morphology of the solid phase can range anywhere from discrete colloidal particles to continuous chain-like polymer networks. It is during the sol-gel process of the inorganic resin that the inorganic heat conductive powder is added into the inorganic resin to form the thermal conductive ceramic coating 23. Preferably, the inorganic heat conductive powder of the thermal conductive ceramic coating 23 has at least one material selected from the group consisting of graphite, graphene, Titanium dioxide, Silicone carbide, and mica, so as to increase the heat conductivity of the ceramic coating 23.

FIG. 2 is a partly, enlarged view of the ceiling panel 2. It is understood that the illustration of FIG. 2 is not to scale, to better clarify the present discussion. In fact, the metal substrate 21 has a thickness of about 0.6 mm. The heat insulating coating 22 has a thickness of from 0.2 to 0.5 mm, preferably from 0.3 to 0.4 mm. Thermal conductive ceramic coating 23 is extremely thin with a thickness in the range of about 10 to 30 μm, preferably of about 15 to 20 μm. Even though the thermal conductive ceramic coating 23 is extremely thin; however, it has excellent durability, rigidity and high thermal stability performance.

It should be noted that a conventional ceiling panel made of gypsum may be covered with a sheet of a reflective metallic material, such as aluminum foil. However, unlike the aluminum foil which is disposed on top of the gypsum core, the metal substrate 21 of the present invention is placed underneath the heat insulating coating 22 and serves merely as a support for the heat insulating coating 22, and not for thermal insulation. Indeed, the metal substrate 21 together with the thermal conductive ceramic coating 23 below is provided to facilitate the heat exchange at the junction between the air in the air-conditioned room and the ceiling panel 2. Thus, all the ceiling panels 2, with the air circulation by the fan 3, can actively facilitate the rapid cooling of the air-conditioned room and keep the room at a uniform temperature. Experimental evidence has shown that when the dropped ceiling 100 together with a fan (such as a ceiling fan or a circulation fan) is employed in an air-conditioned room, the temperature of the room can be further reduced by about 1 to 3 degrees Celsius. That is, the amount of cooling originally required by the air conditioner 4 is reduced. Thus, the dropped ceiling 100 can be used to save a great deal of money in energy bills and to reduce energy consumption in offices and/or homes.

It should be evident that this disclosure is by way of example and that various changes may be made by adding, modifying or eliminating details without departing from the fair scope of the teaching contained in this disclosure. 

What is claimed is:
 1. A ceiling panel, comprising: a thermal conductive metal plate having a top surface, a bottom surface and a peripheral edge surrounding the top surface and the bottom surface; a heat insulating coating formed on the entire top surface of the thermal conductive metal plate, and having a thickness of from 0.2 to 0.5 mm and having less thickness than the thermal conductive metal plate, wherein the heat insulating coating comprises acrylic resin and nanoporous silica; and a thermal conductive ceramic coating formed on the entire bottom surface of the thermal conductive metal plate, and having a thickness in the range of about 10 to 30 μm and having less thickness than the heat insulating coating, wherein the thermal conductive ceramic coating comprises an inorganic resin doped with inorganic heat conductive powder.
 2. A ceiling panel as recited in claim 1, wherein the inorganic heat conductive powder of the thermal conductive ceramic coating has at least one material selected from the group consisting of graphite, graphene, Titanium dioxide, Silicone carbide, and mica. 